Artificial limb and valve therefor



April 30, 1957 Filed Nov. 7, 1955 A. F. HAUSER ARTIFICIAL LIMB AND VALVETHEREFOR 2 Sheets-Sheet 2 ATTORNEY) Unite The present invention relatesin general to the art of prosthetics and more particularly to artificiallegs of the suction, socket type.

This type of prosthesis is usually provided with a spring closed reliefvalve acting as a pop valve arranged to be opened momentarily to permitrelease of air from the socket, when placing the shortened limb in thesocket and thereby establish a suitable degree of partial vacuum forholding the prosthesis in place. Such valves are also used to admit airat the will of the wearer to permit ready removal of the prosthesis, towhich end the valve is provided with manually operated means formomentarily opening the same against the tension of its closing spring.

Some users of this type of prosthesis often experience a discomfortingdisturbance of circulation in the limb on which the prosthesis is worn,due to what is believed to be the building up of an unduly high degreeof partial vacuum during walking, particularly in warm humid weather.

It has been found that temporary relief from the above mentioneddiscomfort may be obtained by momentarily opening the valve by hand butwith the annoyance of having to do so repeatedly at short intervalswhile walking, sometimes as frequently as every 50 feet.- A furtherannoyance incidental to this expedient is that the sudden releasethrough the valve of any difference of pressure between the interior ofthe socket and the outside atmosphere is accompanied by an unpleasantnoise embarrassing to the wearer. Any attempt to remedy the situation byuse of a pressure controlled valve for maintaining the degree of partialvacuum or sub-atmospheric pressure constant at all times during wear, isnot desirable as the degree of sub-atmospheric pressure foundcomfortable for one condition of weather would not be the same underother conditions.

An object of the present invention is to provide a prosthesis of thesuction, socket type in which the aforementioned objections areeliminated.

Another object is to provide a prosthesis of the present type in whichthe attainment of a satisfactory adjustment for a given operatingcondition may be discontinued for any length of time and reproduced withaccuracy and without resort to trial and error procedure.

A further object is the provision of a prosthesis of the suction, sockettype in which the average internal pressure during walking may bemaintained substantially, constant without sudden release or intake ofair sufficient to produce undesirable noise.

Other objects and advantages of the invention will become apparent froma perusal of the following specification and the drawings accompanyingthe same.

In the drawings:

Fig. 1 is a side face view of a portion of a leg prosthesisincorporating the invention, showing an' outside view of the valvecontrol.

Fig. 2 is a vertical fragmentary cross section taken on the line 22 ofFig. 1.

Referring to the drawings in detail, the numeral Patent v O indicates aportion of the wall of the socket of a leg prosthesis of the suctionsocket type. It will be understood that as is customary in a prosthesisof the present type, the socket member is formed in any known or othersuitable manner to have its inner side walls conform to the contour ofthe limb on which it is to be Worn in a substantially airtight fitleaving a small enclosed free space at the bottom, and may be lined withsuitable padding material as is customary in the art. For the sake ofsimplicity and clearness of disclosure, such padded lining and otherusual inside and outside wall coverings are omitted, the wall structurebeing here shown as of one material. It is also to be noted that for thesake of clearness, the .parts are shown greatly enlarged toapproximately four times the actual size so that while the free spaceappears large in the drawing, it is really quite small in relation tothe size of the socket.

Mounted in the wall 10 of the socket near the bottom of the socketchamber is a valve casing 12 extending through from the outside of thewall to the interior wall face 13 of the socket chamber in the enclosedspace below the space occupied by the end of the shortened limb 14 of awearer. The valve casing is provided near its inner end with externalthreads 15 which engage internal threads in the circular opening 16 inthe socket wall to hold the casing in place with the flange 17 seated ina rabbet at the outer rim of the opening against a sealing gasket 18.The valve body 19 of a leak valve designated as a whole at 20 is securedin the casing by means of a clamping nut 21 threaded on to the reducedend of the valve body, the latter extending through an opening 22 in theinner wall of the casing to receive the nut outside the casing wallwhereby the nut bearing against the casing wall clamps the valve inplace with the outer flange portions 23 seated in a rabbeted rim portion24 at the outer open end of the valve casing. A bore or duct 25extending through the reduced portion 26 of the valve body terminates inthe enlarged portion of the valve body in a conical valve seat 27 fromthe face of which valve seat extends a duct 28 through to the outside ofthe valve body into communication with the interior of the valve casing12. Fitted into the conical valve seat is a complementary conical valvehead 29 mounted for rotation in the valve seat by means of the attachedvalve shaft or stem 30 having bearing near the end remote from the headin a round bearing block 31. The round bearing block is threaded on itsperiphery to engage internal threads 32 in the inner wall of acylindrical valve-spring chamber 33 formed in the enlarged portion ofthe valve body. A valve spring 34 in the form of a cylindricalcoilcompression spring surrounds the valve stem, bearing at one end againstthe bearing block 31 and at the other end against the valve head 29.

The valve head 29 has formed therein an axial bore or manifold duct 35in constant communication With the duct 25 and a plurality of radialpassages or ducts 36 which latter extend to the conical surface forcommunication with the valve seat duct 28 selectively as the valve headis turned. Venting ducts 46 in the valve body flange 23 serve to ventthe valve casing to atmosphere. Turning of the valve stem 30 and head 29is effected manually through a hand bar 37 mounted on the reducedsquared end 38 of the valve stem and clamped thereto by a watch screw39. A disk 40 integral with the bar 37 or otherwise arranged to movetherewith has a radially extending index arm 41 cut free of the disk oneach side as shown in Fig. 1. Indexing characters 42 in theform ofnumbers are applied to the flange 23 in any known or other suitablemanner, as by engraving, to indicate the angular posit-ions in which theindex 'arm is to be placed for selectively bringing any one of theradial channels 36 into communication with the duct 28 or for closingoit' all the'radial ducts 36 as the case may be. In the presentinstance,the index characters take the form of numbers indicating the diametersof the ducts which they represent inthousandthsof aninch, the indexOTindieating, that. with the 'index armpointingtoward'this index, thereis no communication between the manifold duc t 35 and the duct 28, orthat the valve is in the off position.

*Spring loaded detent means, for holding the index arm in any one of itsindexed positions againstlight force, is provided in the form ofindentations or sockets 43 in the outer face of the flange 23 to receivea downwardly projecting boss 44 stamped in the index arm 41. In theembodiment here shown there are five such indexed positions marked 0, 3,6, 9, and 12, representing zero leakage, or connection of a leakage ductof 3, 6, 9 or 12 thousandths oi an inch in diameter, respectively.

A positive stop for'the index arm and consequently for. the valvemovement at the zero position is provided by a stop post 45 mounted inthe fiange 23 near the zero index character to project into the path ofthe index arm 41 at a point spaced slightly counterclockwise of the zeroindex character. Thus the valve adjustment may readily be brought tothezero position from any position, say that shown in Fig. l, by turningthe hand bar 37 counterclockwise until the arm strikes the stop post 45.This may be accomplished by manipulation of the device through theclothing of a wearer, and establishes a reference point from whichadjustment of the valve may be made also through the clothing, to selectany one of the predetermined rates of leakage. A quick venting of thesocket chamber for release of either vacuum or pressure may be had by aslight outward pull on the hand bar 37 against the tension of thevalve-seating spring 34 to temporarily'withdraw the conical valve headfrom its seat to momentarily provide a direct connection between theducts 25 and 28. Where it is desired to maintain the full venting for anindefinite length of time, the index arm in the raised position may bemoved over and rested upon the stop post 45 to hold the valve head offthe seat. This full venting is of course of special-advantage inapplying and removing the prosthesis.

With the prosthesis in use, in walking, there is a tendency'tocontinuously increase the difference in pressure between the interior ofthe socket and the outside atmosphere to a point where the userexperiences discomfort apparently due to circulatory disturbance,however with maintainance of a proper given slow leakage path betweenthe socket chamber and the outside atmosphere this tendency is ofiset.

As the optimum degree of resistance to air flow required tosubstantially offset the above mentioned tendency to pressure change,varies with weather conditions stantially air tight fit to the stump ofa patients limb, meanrpravramg a pluralism*fixeaneakage"enamels betweenthe interior of the socket and the outside atmosphere, each of saidchannels having a difierent fixed resistance to the passage of airtherethrough, and means for selectively maintaining any one of saidchannels open.

2. An artificial limb comprising a socket member adapted to receive thestump of a patients limb, said socket member being formed with a chamberadapted to be fitted to the stump in a substantially air tight fit withthe side walls of the chamber and with a-relatively small free spacebetween the bottom end of the stump and the bottom of the chamber,meansproviding a plurality of fixed leakage channels between the saidfree space and the outside atmosphere, said channels having ditierentfixed resistances to air flow therethrough, and means for selectivelymaintaining any one of said channels open.

3. An artificial limb comprising a socket member adapted to be fittedwith a substantially air-tight fit to the stump of a patients limb whileleaving a relatively small space between the bottom of the stump and thebottom of the socket, means providing a plurality of nor mally closedair leakage channels of diflerent diameters between the said small spaceand the outside of the socket member, and means for selectivelymaintaining any one of said channels open;

4. An artificial limb comprising a socket member adapted to be 'fittedwith a substantially air tight fit to the stump of a patients shortenedlimb while leaving a relatively small space between the bottom of thestump and the bottom of the socket, means providing a plurality of airleakage channels of different diameters, and a distributing valve meansselectively connecting any one of said channels between the said smallspace in the socket and the outside atmosphere to establish apredetermined leakage path between the said space and the outsideatmosphere.

.5. An artificial limb comprising -a socket member adapted to be fittedwith a substantially air tight fit over the end of the stump of apatients limb whileleaving a relatively small enclosed air space betweenthe end of the stump and the bottom of the socket, means providing aplurality of circular leakage channels of ditferent diameters rangingfrom approximately 3 thousandths to l2 thousandths of an inch, andselector valve means sesuch as temperature and humidity, adjustment to'such variations is afforded by provision of the plurality of ducts ofvarying resistance to air flow. While in the present embodiment thedifierent degrees of resistance to air flow is accomplished by use ofducts of difierent areas of cross-section, it will be understood thatvariation in resistance of the different ducts may be accomplishedby anyknown or other suitable means as by packing with a porous filling suchas steel wool or equivalent.

While a single preferred embodiment of the invention has been hereinshown and described for the sake of disclosure, it is to be understoodthatthe invention is not limited to such specific embodiment:butcontemplates all suchmodificationsand variants thereof as fall-fairlyformed with a chamber adapted to' be'fitted with a sub-.

lectively connecting-any one of said channels between said air space andthe outside atmosphere.

6.'An artificial limb comprising a socket member adapted to be fittedwith a substantially air tight fit over the endof a patients shortenedlimb while leaving a relatively small space between the end of theshortened limb and the bottom of the socket, means providing a pluralityof leakage channels having different areas of cross'sectionapproximately equal to those ofcircular channels of av diameter of 3thousandths to 12 thousandths of an inch, and selectorivalve meansselectively connecting any one of said channels between said small spacein the socket and the outside atmosphere.

'YJAn' artifiCiaI climb comprising a socket member formed with a chamberadapted to be fitted with 'a'sujbstantially air tight fit, to the stumpof a patients leg, a conical valve seat member having a pair of openingstherein one at the apex of the valve seat in communication with theinterior of said socket chamber and the other in the side wall of theconical valve seat in communication with the outside atmosphere, theopening in the side walllying 'in' a given plane transverse to theaxis'of the conical valve 'seat, a conical valve head seated in saidvalve seat and having a manifold duct extending through the apex end ofthe conical valve head in communication with the said valve seat openingat the apex of the seat, a plurality of leakage ducts in the valve headleading from the manifold duct each to a different point at-the conicalsurface of the'valve head in said given plane in which lies the saidopening" in the-side wall of the valve seat, EElClFOf'Sald leakage ductshaving'a difierent resistance to fluid flow, spring means urging thevalve head against the seat, and manually operated means accessible fromoutside the socket member mechanically connected with the valve head forrotating the head and for lifting the head clear of the seat to providea space between valve head and valve seat in direct communication withboth said pair of openings in the valve seat for quick equalization ofpressure between the interior of the socket and the outside atmosphere.

8. An artificial limb comprising a socket member adapted to be fittedwith a substantially air tight fit to the stump of a patients limb, aspring-loaded relief valve connected to vent the interior of the socketmember to the outside atmosphere, said relief valve having a rotatablevalve head normally engaging a valve seat under spring pressure, andselective aperture means connecting the interior of the socket memberwith the outside atmosphere through the valve seat and valve head andselective with rotation of the valve head.

References Cited in the file of this patent FOREIGN PATENTS 808,975Kowsky July 23, 1951

